Power distribution systems and methods of operating power distribution systems with a communication network

ABSTRACT

An example electrical power distribution system includes a plurality of circuit protection devices coupled between an electrical power source and a plurality of electrical loads. Each circuit protection device includes a trip unit, a network interface, a processor, and a memory. The trip unit is configured to selectively trip to prevent a flow of electrical current through said circuit protection device. The network interface is communicatively coupled to a communication network including the plurality of circuit protection devices. The memory stores instructions that, when executed by the processor, cause the processor to transmit, using the network interface, circuit protection device data to the network. The circuit protection device data is formatted according to a network communication protocol of the communication network.

BACKGROUND

The present application relates generally to power distribution systemsand, more particularly, to methods of operating power distributionsystems including a communication network.

Known power distribution systems include a plurality of switchgearlineups including circuit breakers that are each coupled to one or moreloads. The circuit breakers typically include a trip unit that controlsthe circuit breakers based upon sensed current flowing through thecircuit breakers. More specifically, the trip unit causes currentflowing through the circuit breaker to be interrupted if the current isoutside of acceptable conditions.

Some known circuit breakers are programmed with one or more currentthresholds (also known as “pickup” thresholds) that identify undesiredcurrent levels for the circuit breaker. If a fault draws current inexcess of one or more current thresholds for a predetermined amount oftime, for example, the trip unit typically activates the associatedcircuit breaker to stop current from flowing through the circuitbreaker. However, in power distribution systems that include a pluralityof circuit breakers, a typical arrangement uses a hierarchy of circuitbreakers. Large circuit breakers (i.e., circuit breakers with a highcurrent rating) are positioned closer to a power source than lowercurrent feeder circuit breakers and feed the lower current feedercircuit breakers. Each feeder circuit breaker may feed a plurality ofother circuit breakers, which connect to loads or other distributionequipment.

A fault may occur anywhere in the circuit breaker hierarchy. When afault occurs, each circuit breaker that has the same fault currentflowing through it may detect different amounts of fault current as aresult of varying sensor sensitivities and/or tolerances. When the faultoccurs, the circuit breaker closest to the fault should operate to stopcurrent from flowing through the circuit breaker. If a circuit breakerhigher in the hierarchy trips, multiple circuits or loads mayunnecessarily lose service.

To accommodate for the varying tolerances and to ensure that multiplecircuit breakers do not unnecessarily trip based on the same faultcurrent, the current thresholds of at least some known circuit breakersare nested with each other to avoid overlapping fault currentthresholds. In some other known systems, circuit breakers in a lowertier send coordination or blocking signals to higher tier circuitbreakers upon detection of a fault current and the upper tier circuitbreakers' operation is coordinated with the operation of the lower tiercircuit breaker in response to the blocking signal. The signals aretypically transmitted over a dedicated connection between a blockingsignal output in the lower tier circuit breaker and a blocking signalinput in each upper tier circuit breaker with which the lower tiercircuit breaker must be coordinated. The blocking/coordination signalsare typically a simple binary (on/off) signal in which the presence of avoltage indicates a blocking signal and the absence of a voltageindicates the absence of a blocking signal. Some known systemsincorporate a third signal, such as a periodic pulse, to add anadditional indication, such as to confirm there is no blocking signalbut the connection between circuit breakers is still functioning. Suchknown systems do not provide any additional information from the lowertier circuit breaker to the upper tier circuit breakers in connectionwith the blocking signal.

In certain system topologies, circuit breakers known as ties, whichconnect distribution busses in the same tier of a system with multiplesources supplying multiple busses, cannot detect fault currentdirection. The trip unit in the tie does not know whether current isflowing through the tie from right to left or left to right. When afault occurs the tie must send a blocking signal to upper tier deviceson all connected sources. This results in the undesirable operation thatall source devices are blocked when it may otherwise be desired that atleast one of them not be blocked.

At least some known power distribution systems include circuitprotection devices operable in at least two protection modes: a normalprotection mode and a maintenance mode. In the normal protection mode,current thresholds (also known as “pickup” thresholds) that identifyundesired current levels are set to protect equipment, such as a load orother protection devices. The maintenance mode is commonly activated bya person when the person will be interacting with a load or protectiondevice downstream (in a lower tier) from a protection device. In themaintenance mode, the protection device's settings are adjusted to makeit more sensitive to undesired current levels and, if possible, decreasethe amount of time needed by the protection device to react to anundesired current level. Thus, a protection device is easier and/orquicker to trip when the maintenance mode is enabled. The maintenancemode of a protection device is typically manually enabled and disabledby a person. Failure of a person to enable a maintenance mode in aprotection device in some known systems increases the danger to a personworking downstream from the protection. Failure to return the protectiondevice from the maintenance mode to the normal protection mode mayincrease the likelihood that the protection device will tripunnecessarily.

At least some known power distribution systems include circuitprotection devices with ground fault detection capabilities. A circuitprotection device that disconnects a circuit when it detects thatelectric current is not balanced between conductors, for example betweena line conductor and a neutral conductor, may be referred to as aresidual current device (RCD). RCDs include, for example, ground faultcircuit interrupters (GFCIs), ground fault interrupters (GFIs),appliance leakage current interrupters (ALCIs), residual-current circuitbreakers with overload protection (RCBOs), and electronicresidual-current circuit breakers with overload protection (eRCBOs).Ground fault detection capabilities of a circuit protection device areoften controlled based only on data that is collected directly by thecircuit protection device without full knowledge concerning operation ofother circuit protection devices or other portions of the powerdistribution system.

Some known power systems utilize relatively simple circuit protectiondevices in connection with a centralized controller. The centralizedcontroller receives data from sensors disposed throughout the powerdistribution system. The centralized controller commands and coordinatesoperation of the various circuit protection devices in the powerdistribution system based on the sensed data.

BRIEF DESCRIPTION

In one aspect, an electrical power distribution system includes aplurality of circuit protection devices coupled between an electricalpower source and a plurality of electrical loads. Each circuitprotection device includes a trip unit, a network interface, aprocessor, and a memory. The trip unit is configured to selectively tripto prevent a flow of electrical current through said circuit protectiondevice. The network interface is communicatively coupled to acommunication network including the plurality of circuit protectiondevices. The memory stores instructions that, when executed by theprocessor, cause the processor to transmit, using the network interface,circuit protection device data to the network. The circuit protectiondevice data is formatted according to a network communication protocolof the communication network.

Another aspect is a circuit protection device including a trip unit, anetwork interface, a processor, and a memory. The trip unit isconfigured to selectively trip to prevent a flow of electrical currentthrough said circuit protection device. The network interface iscommunicatively coupled to a communication network including theplurality of circuit protection devices. The memory stores instructionsthat, when executed by the processor, cause the processor to transmit,using the network interface, circuit protection device data to thenetwork. The circuit protection device data is formatted according to anetwork communication protocol of the communication network.

In yet another aspect, a method of operating an electrical powerdistribution system including a plurality of circuit protection devicescoupled between an electrical power source and a plurality of electricalloads is disclosed. Each circuit protection device of the plurality ofcircuit protection devices includes a trip unit, a network interfacecommunicatively coupled to a communication network including theplurality of circuit protection devices, a processor, and a memory. Themethod includes transmitting, by one of the circuit protection devices,identification data to the other circuit protection devices of theplurality of circuit protection devices over the communication network.The one of the circuit protection devices receives identification datafrom the other circuit protection devices of the plurality of circuitprotection devices over the communication network and stores theidentification data from the other circuit protection devices in itsmemory.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic block diagram of an exemplary power distributionsystem.

FIG. 2 is a diagram of a wireless communication configuration of thepower distribution system shown in FIG. 1.

FIG. 3 is a diagram of a wired communication configuration of the powerdistribution system shown in FIG. 1 that also provides wireless accessto a user.

FIG. 4 is a diagram of another wireless communication configuration ofthe power distribution system shown in FIG. 1.

FIG. 5 is a diagram of another wireless communication configuration ofthe power distribution system shown in FIG. 1.

FIG. 6 is a diagram of another wired communication configuration of thepower distribution system shown in FIG. 1 that also provides wirelessaccess to a user.

FIG. 7 is a diagram of a hybrid communication configuration of the powerdistribution system shown in FIG. 1 including wired and wirelesscommunication within the power distribution system.

FIG. 8 is a flow diagram of an example method of operating an electricalpower distribution system.

FIG. 9 is a flow diagram of another example method of operating anelectrical power distribution system.

FIG. 10 is an example configuration of a portion of the powerdistribution system shown in FIG. 1.

FIG. 11 is a flow diagram of an example method of coordinatedmaintenance mode operation of an electrical power distribution system.

FIG. 12 is a flow diagram of an example method of coordinated groundfault detection operation of an electrical power distribution system.

FIG. 13 is a data flow diagram of an exemplary power distribution systemsimilar to the electrical power distribution system shown in FIG. 1 fortesting the response of the system to various electrical conditions.

FIG. 14 is a data flow diagram of the power distribution system shown inFIG. 13 during exemplary testing for zone selective interlock (ZSI).

FIG. 15 is a data flow diagram of the power distribution system shown inFIG. 13 during exemplary testing maintenance modes for circuitprotection devices.

DETAILED DESCRIPTION

In the following specification and the claims, reference will be made toa number of terms, which shall be defined to have the followingmeanings.

The singular forms “a”, “an”, and “the” include plural references unlessthe context clearly dictates otherwise.

“Optional” or “optionally” means that the subsequently described eventor circumstance may or may not occur, and that the description includesinstances where the event occurs and instances where it does not.

Approximating language, as used herein throughout the specification andclaims, may be applied to modify any quantitative representation thatcould permissibly vary without resulting in a change in the basicfunction to which it is related. Accordingly, a value modified by a termor terms, such as “about”, “approximately”, and “substantially”, are notto be limited to the precise value specified. In at least someinstances, the approximating language may correspond to the precision ofan instrument for measuring the value. Here and throughout thespecification and claims, range limitations may be combined and/orinterchanged, such ranges are identified and include all the sub-rangescontained therein unless context or language indicates otherwise.

As used herein, the terms “processor” and “computer” and related terms,e.g., “processing device”, “computing device”, and “controller” are notlimited to just those integrated circuits referred to in the art as acomputer, but broadly refers to a microcontroller, a microcomputer, aprogrammable logic controller (PLC), an application specific integratedcircuit (ASIC), and other programmable circuits, and these terms areused interchangeably herein. In the embodiments described herein, memorymay include, but is not limited to, a computer-readable medium, such asa random access memory (RAM), and a computer-readable non-volatilemedium, such as flash memory. Alternatively, a compact disc-read onlymemory (CD-ROM), a magneto-optical disk (MOD), and/or a digitalversatile disc (DVD) may also be used. Also, in the embodimentsdescribed herein, additional input channels may be, but are not limitedto, computer peripherals associated with an operator interface such as amouse and a keyboard. Alternatively, other computer peripherals may alsobe used that may include, for example, but not be limited to, a scanner.Furthermore, in the exemplary embodiment, additional output channels mayinclude, but not be limited to, an operator interface monitor.

Further, as used herein, the terms “software” and “firmware” areinterchangeable, and include any computer program stored in memory forexecution by personal computers, workstations, clients and servers.

As used herein, the term “non-transitory computer-readable media” isintended to be representative of any tangible computer-based deviceimplemented in any method or technology for short-term and long-termstorage of information, such as, computer-readable instructions, datastructures, program modules and sub-modules, or other data in anydevice. Therefore, the methods described herein may be encoded asexecutable instructions embodied in a tangible, non-transitory, computerreadable medium, including, without limitation, a storage device and/ora memory device. Such instructions, when executed by a processor, causethe processor to perform at least a portion of the methods describedherein. Moreover, as used herein, the term “non-transitorycomputer-readable media” includes all tangible, computer-readable media,including, without limitation, non-transitory computer storage devices,including, without limitation, volatile and nonvolatile media, andremovable and non-removable media such as a firmware, physical andvirtual storage, CD-ROMs, DVDs, and any other digital source such as anetwork or the Internet, as well as yet to be developed digital means,with the sole exception being a transitory, propagating signal.

Exemplary embodiments of power distribution systems and methods ofoperating power distribution systems are described herein. The exemplarypower distribution systems include circuit protection devices organizedin a wired and/or wireless communication network. The circuit protectiondevices are able to transmit circuit protection device data formatted ina communication protocol to each other in over the communication networkto provide each circuit protection device with detail about theconfiguration, operation, and current status of the power distributionsystem and the circuit protection devices in the system. The sharedinformation allows circuit protection device operation to be coordinatedbased on more complete information than some known systems.

FIG. 1 is a schematic block diagram of a portion of an exemplaryelectrical power distribution system 100 including sources 102 providingpower to loads 104 via circuit protection devices 106. Electrical powersources 102 may include, for example, one or more generators, electricalgrids, or other devices that provide electrical current (and resultingelectrical power) to loads 104. The electrical current may betransmitted to loads 104 through distribution busses 108. Loads 104 mayinclude, but are not limited to only including, machinery, motors,lighting, and/or other electrical and mechanical equipment of amanufacturing or power generation or distribution facility. Althoughconnections between components in system 100 are illustrated with asingle line for simplicity, it should be understood that system 100 willinclude multiple electrical connections between components, such as aline connection, a neutral connection, and a ground connection.Moreover, some embodiments are multiphase systems including a separateline connection for each phase of electricity.

In some embodiments, circuit protection devices 106 are housed in one ormore switchgear units (not shown in FIG. 1). The switchgear unitsinclude racks to which circuit protection devices 106 are mounted withina cabinet. Circuit protection devices 106 that are electrically close toeach other may be disposed physically close to each other, such as inthe same switchgear unit, or physically distant from each other, such asin separate switchgear units, in separate rooms, etc. Similarly, circuitprotection devices 106 that are electrically distant from each other maybe disposed physically close to each other or physically distant fromeach other.

In the illustrated embodiment, circuit protection devices 106 arearranged in a hierarchy including a first tier 110 and a second tier 112to provide different levels of protection and monitoring to powerdistribution system 100. For example, a first circuit protection device114 (sometimes referred to as a source circuit protection device) isarranged in first tier 110 to receive current from a first electricalpower source 116 and provide current to a first bus 118. A secondcircuit protection device 120 (sometimes referred to as a feeder circuitprotections device) is arranged in the second tier 112 downstream offirst circuit protection device 114 and connected to receive currentfrom first bus 118. Second circuit protection device 120 providescurrent to a first load 122. As used herein, the term “downstream”refers to a direction from electrical power source 102 towards load 104.The term “upstream” refers to a direction opposite the downstreamdirection, for example, from load 104 towards electrical power source102. While FIG. 1 illustrates circuit protection devices 106 arranged intwo tiers 110 and 112, it should be recognized that any suitable numberof circuit protection devices 106 may be arranged in any suitable numberof tiers to enable power distribution system 100 to function asdescribed herein. For example, it should be recognized that one or moreadditional tiers and/or circuit protection devices 106 may be disposedbetween electrical power source 102 and first tier 110 in someembodiments. Additionally or alternatively, one or more additional tiersand/or circuit protection devices 106 may be disposed between load 104and second tier 112 circuit protection devices 106 in some embodiments.

The example system 100 includes three distribution busses 108 coupledtogether by two circuit protection devices 106 referred to as ties.First distribution bus 118 is connected to second distribution bus 124by a first tie 126 (also referred to as a first tie circuit protectiondevice). A second tie 128 (also referred to as a second tie circuitprotection device) connects first distribution bus 118 to a thirddistribution bus 130. Although three busses are shown in FIG. 1, powersystem 100 may include any suitable number of busses, including more orfewer than three busses. First tie 126 and second tie 128 are sometimesreferred to herein as source circuit protection devices that areconnected between a source 102 (via distribution bus 124 or 130) andfirst distribution bus 118.

In the exemplary embodiment, circuit protection devices 106 are circuitbreakers. Alternatively, circuit protection devices 106 may be any otherdevice that enables power distribution system 100 to function asdescribed herein. In an exemplary embodiment, each circuit protectiondevice 106 in second tier 112 includes an integrated trip unit. Detailsof an example integrated trip unit are shown for second circuitprotection device 120, and are omitted from other circuit protectiondevices 106 for clarity. Second circuit protection device 120 includes atrip unit 132 operatively coupled to a sensor 134 and a trip mechanism136. Trip unit 132, in an exemplary embodiment, is an electronic tripunit (ETU) that includes a processor 138 coupled to a memory 140, aninput device 142, a display device 144, and a network interface. In someembodiments, trip unit 132 does not include input device 142 and/ordisplay device 144. Trip unit 132 may include, or may be considered tobe, a computing device. In other embodiments, trip units 132 may be anyother suitable type of trip unit. In some embodiments, one or more ofcircuit protection devices 106 include a different type of trip unit 132and/or is a different type of circuit protection device than at leastone other of circuit protection devices 106.

Sensor 134, in an exemplary embodiment, is a current sensor, such as acurrent transformer, a Rogowski coil, a Hall-effect sensor, a fiberoptic current sensor, and/or a shunt that measures a current flowingthrough trip mechanism 136 and/or circuit protection device 106.Alternatively, sensor 134 may include any other sensor that enablespower distribution system 100 to function as described herein. Moreover,sensor 134 may be integrated in a circuit protection device 106 or maybe separate from an associated circuit protection device 106. Differentsensors 134 may be used for different portions of system 100. Forexample, sensors 134 in first tier 110 may be different than sensors 134in second tier 112. Each sensor 134 generates a signal representative ofthe measured or detected current (hereinafter referred to as “currentsignal”) flowing through an associated trip mechanism 136 and/or circuitprotection device 106. In addition, each sensor 134 transmits thecurrent signal to processor 138 associated with, or coupled to, tripmechanism 136. Each processor 138 is programmed to activate tripmechanism 136 to interrupt a current provided to a load 104 or anelectrical distribution line or bus 108 if the current signal, and/orthe current represented by the current signal, exceeds a currentthreshold. Moreover, in some embodiments, processor 138 converts thecurrent signal to the amount (i.e., the magnitude) of electrical currentrepresented by the current signal. Thus, circuit protection devices 106can send communication signals to other circuit protection devices 106that include the amount of current detected rather than a value of thecurrent signal. The receiving circuit protection devices 106 do not needto know what type of current sensor was used to measure the current,thereby permitting circuit protection devices 106 with different typesof current sensors or different models of current sensors to be used ina single system. In other embodiments, circuit protection devices 106send a value of the current signal and the receiving circuit protectiondevices 106 determine the amount of current represented by the currentsignal based on received data about the transmitting circuit protectiondevice 106 (including the type of current sensor used by thetransmitting circuit protection device 106).

In the example embodiment, trip mechanism 136 is a circuit breaker. Anelectric signal is provided to trip mechanism 136 to cause the circuitbreaker to trip and interrupt the flow of current through trip mechanism136. In other embodiments, trip mechanism 136 includes, for example, oneor more other circuit breaker devices and/or arc containment devices.Exemplary circuit breaker devices include, for example, circuitswitches, contact arms, and/or circuit interrupters that interruptcurrent flowing through the circuit breaker device to a load 104 coupledto the circuit breaker device. An exemplary arc containment deviceincludes, for example, a containment assembly, a plurality ofelectrodes, a plasma gun, and a trigger circuit that causes the plasmagun to emit ablative plasma into a gap between the electrodes in orderto divert energy into the containment assembly from an arc or otherelectrical fault that is detected on the circuit.

Each processor 138 controls the operation of a circuit protection device106 and gathers measured operating condition data, such as datarepresentative of a current measurement (also referred to herein as“current data”), from sensor 134 associated with a trip mechanism 136coupled to processor 138. Processor 138 stores the current data in amemory 140 coupled to processor 138. It should be understood that theterm “processor” refers generally to any programmable system includingsystems and microcontrollers, reduced instruction set circuits (RISC),application specific integrated circuits (ASIC), programmable logiccircuits, and any other circuit or processor capable of executing thefunctions described herein. The above examples are exemplary only, andthus are not intended to limit in any way the definition and/or meaningof the term “processor.” In the example embodiments described herein,processor 138 also controls network communication by its circuitprotection device. In other embodiments, processor 138 handlesprotection operations and a separate processor (not shown) handlesnetwork communication.

Memory 140 stores program code and instructions, executable by processor138, to control circuit protection device 106. Memory 140 may include,but is not limited to only include, non-volatile RAM (NVRAM), magneticRAM (MRAM), ferroelectric RAM (FeRAM), read only memory (ROM), flashmemory and/or Electrically Erasable Programmable Read Only Memory(EEPROM). Any other suitable magnetic, optical and/or semiconductormemory, by itself or in combination with other forms of memory, may beincluded in memory 140. Memory 140 may also be, or include, a detachableor removable memory, including, but not limited to, a suitablecartridge, disk, CD ROM, DVD or USB memory.

Input device 142 receives input from, for example, a user. Input device142 may include, for example, a keyboard, a card reader (e.g., asmartcard reader), a pointing device, a mouse, a stylus, a touchsensitive panel (e.g., a touch pad or a touch screen), a gyroscope, anaccelerometer, a position detector, a keypad, a communications port, oneor more buttons, and/or an audio input interface. A single component,such as a touch screen, may function as both display device 144 andinput device 142. Although a single input device 142 is shown, a tripunit 132 may include more than one input device 142 or no input device142.

Display device 144 visually presents information about circuitprotection device 106 and/or trip mechanism 136. Display devices 144 mayinclude a vacuum fluorescent display (VFD), one or more light-emittingdiodes (LEDs), liquid crystal displays (LCDs), cathode ray tubes (CRT),plasma displays, and/or any suitable visual output device capable ofvisually conveying information to a user. For example, processor 138 mayactivate one or more components of display device 144 to indicate thatcircuit protection device 106 and/or trip mechanism 136 is active and/oroperating normally, is receiving a blocking signal, is transmitting ablocking signal, that a fault or failure has occurred, and/or any otherstatus of trip mechanism 136 and/or circuit protection device 106. Insome embodiments, display device 144 presents a graphical user interface(GUI) to a user for interaction between the user and circuit protectiondevice 106. The GUI permits the user, for example, to control circuitprotection device 106, monitor operation/status of circuit protectiondevice 106, test operation of circuit protection device 106, and/ormodify operational parameters of circuit protection device 106.

Network interfaces 146 allows circuit protection devices 106 tocommunicate with each other as well as remote devices and systems aspart of a wired or wireless communication network. Wireless networkinterfaces may include a radio frequency (RF) transceiver, a Bluetooth®adapter, a Wi-Fi transceiver, a ZigBee® transceiver, a near fieldcommunication (NFC) transceiver, an infrared (IR) transceiver, and/orany other device and communication protocol for wireless communication.(Bluetooth is a registered trademark of Bluetooth Special Interest Groupof Kirkland, Wash.; ZigBee is a registered trademark of the ZigBeeAlliance of San Ramon, Calif.) Wired network interfaces may use anysuitable wired communication protocol for direct communicationincluding, without limitation, USB, RS232, I2C, SPI, analog, andproprietary I/O protocols. Moreover, in some embodiments, the wirednetwork interfaces include a wired network adapter allowing thecomputing device to be coupled to a network, such as the Internet, alocal area network (LAN), a wide area network (WAN), a mesh network,and/or any other network to communicate with remote devices and systemsvia the network. Circuit protection devices 106 transmit and receivecommunications over the communication network using messages formattedaccording to an appropriate network communication protocol. In someembodiments, the network communication protocol is an Ethernetcommunication protocol or an Institute of Electrical and ElectronicsEngineers (IEEE) 802.11 based communication protocol.

By communicatively coupling circuit protection devices 106 together in acommunication network, circuit protection devices 106 are able tocommunicate detailed data to each other beyond simple binary commands.Moreover, the communication network allows circuit protection devices106 to communicate with all circuit protection devices 106communicatively coupled to the communication network. In variousembodiments, circuit protection devices 106 are configured to transmitvarious types of circuit protection device data, such as measuredelectrical current, operating parameters and settings, intended actions,device identification data, maintenance status, error data, other sensordata, data received from other circuit protection devices, and the like,to the communication network for receipt by the other circuit protectiondevice 106 coupled to the network. Circuit protection devices 106 areable to cooperate with each other to provide protection based on morecomplete data about the overall system than might otherwise be availablein a power distribution system without a centralized controller.

Additionally, circuit protection devices are configured, such as byinstructions stored in memory 140 and executed by processor 138, to becapable of communication with devices outside of power distributionsystem 100. Thus, a user may establish communication with circuitprotection devices 106 using a remote access device (not shown in FIG.1), such as a computer, a laptop computer, a tablet computer, asmartphone, a personal digital assistant (PDA), a dedicated powerdistribution system communication device, or the like. The remote accessdevice can be used for any suitable purpose including, for example,reviewing and/or changing circuit protection device settings, monitoringoperation of circuit protection devices 106, remotely controllingcircuit protection device setting, initiating tests of circuitprotection devices, and the like.

In various embodiments, as described in more detail below, circuitprotection devices 106 are configured into a communication networkaccording to any suitable network communication configuration. Thecommunication network may be a wired network, a wireless network, or acombination of wired and wireless network. In some embodiments, circuitprotection devices 106 communicate directly with each other circuitprotection device 106 or remote access device within range of itscommunication signals. In some embodiments, circuit protection devices106 communicate directly with one or more circuit protection devices 106that act as network switches to direct communication between circuitprotection devices 106 and any remote access devices. In someembodiments, circuit protection devices 106 are configured as a meshnetwork, while in some embodiments a network switch or router isincluded within or without the switchgear units of power distributionsystem 100. Two or more of above-described configurations, as well asany other suitable configurations, may be combined in power distributionsystem 100 in some embodiments.

FIGS. 2-7 are diagrams of several example communication configurationsof power distribution system 100. In FIGS. 2-7 common reference numbersrefer to similar components serving similar functions, unless otherwisenoted. In each configuration, power distribution system 100 is disposedwithin switchgear unit 202 surrounded by an arc flash safety boundary204. Although a single switchgear unit and four circuit protectiondevices 106 are illustrated, power distribution system 100 may includemore or fewer circuit protection devices 106 and may be disposed in morethan one switchgear unit in various embodiments of each communicationconfiguration. Network communication between circuit protection devicesin separate switchgear units may be wired or wireless communication.

FIG. 2 is a diagram of a wireless communication configuration 200 ofpower distribution system 100. This configuration utilizes a singledevice as the wireless system's access point. Each circuit protectiondevice's network interface 146 is a wireless network interface 146connected to an antenna 206. A first circuit protection device 208 isconfigured to function as an access point for the communication network.In some embodiments, first circuit protection device may alsocommunicatively couple the communication network to circuit protectiondevices 106 disposed in a separate switchgear unit. In the illustratedembodiment, each circuit protection device 106 is wirelessly,communicatively coupled to first circuit protection device 208 throughwireless signals 209. Each circuit protection device 106 communicates toother devices coupled to the communication network through first circuitprotection device 208. A user 210 may access the communication network,and accordingly circuit protection devices 106, using a remotecommunication device, such as laptop computer 212 or smartphone 214.Laptop 212 and smartphone 214 are wirelessly, communicatively coupled tothe communication network through first circuit protection device 208.

FIG. 3 is a diagram of a wired communication configuration 300 that alsoprovides wireless access to user 210. This configuration allows a userdevice to wirelessly connect to a wired system using a single device,with that device acting as an access point. Each circuit protectiondevice's network interface 146 includes a wired network interface 146.Circuit protection devices 106 are connect by network cables 302 to anetwork switch 304 to form the communication network. Network interface146 of first circuit protection device 208 also includes a wirelessnetwork interface 146. Although illustrated as a single networkinterface 146, first circuit protection device may include separatewireless and wired network interfaces 146. First circuit protectiondevice 208 is configured to function as a network bridge (also referredto sometimes herein as an access point) to facilitate wireless access tothe wired communication network. Generally, each circuit protectiondevice 106 communicates to other devices coupled to the communicationnetwork through network switch 304. A second circuit protection device306 is indirectly coupled to network switch 304 through a third circuitprotection device 308. User 210 may access the communication network,and accordingly circuit protection devices 106, using a remotecommunication device wirelessly, communicatively coupled to the wiredcommunication network through first circuit protection device 208.

FIG. 4 is a diagram of another wireless communication configuration 400of power distribution system 100. This configuration allows the user toconnect wirelessly in a peer-to-peer fashion to any chosen device. Eachcircuit protection device's network interface 146 includes a wirelessnetwork interface 146. In this configuration, none of circuit protectiondevices 106 functions as an access point. Rather, each circuitprotection device 106 wirelessly communicates directly with the intendedcommunication destination, e.g., a peer-to-peer network. Direct wirelesscommunication is also used for communication between circuit protectiondevices 106 and remote communication devices 212 and 214.

FIG. 5 is a diagram of a wireless communication configuration 500 inwhich a wireless access point 502 is disposed outside of switchgear unit202. This configuration allows the user to connect to the systemwirelessly using an external access point device. Circuit protectiondevices 106 and remote communication devices 212 and 214 are wirelessly,communicatively coupled to wireless access point 502. Networkcommunication is transmitted wirelessly to wireless access point 502,which transmits the communication to its intended destination.

FIG. 6 is a diagram of another wired communication configuration 600that also provides wireless access to user 210. Each circuit protectiondevice's network interface 146 includes a wired network interface 146.Circuit protection devices 106 are connect by network cables 302 tonetwork switch 304 to form the communication network. An access point602 is disposed outside of switchgear unit 202. Access point 602includes a wired network interface 604 and a wireless network interface606. Access point 602 is connected to network switch 304 by a networkcable 302. Wireless network interface 606 provides wireless connectivityto remote communication devices 212 and 214.

FIG. 7 is a diagram of a hybrid communication configuration 700 of powerdistribution system 100 including wired and wireless communicationwithin power distribution system 100. An access point 702 is disposedwithin of switchgear unit 202. Access point 602 includes a wired networkinterface 704 for wired connection to circuit protection devices 106 anda wireless network interface 706 for wired connection to circuitprotection devices 708. Access point 602 is connected to network switch304 by a network cable 302. The wireless network interface of accesspoint 602 provides wireless connectivity to remote communication devices212 and 214.

The example communications configurations 200, 300, 400, 500, 600, and700 may be combined in any suitable combination of wired and wirelessconnectivity across any number of circuit protection devices 106disposed in one or more switchgear units 202.

FIG. 8 is a flow diagram of an example method 800 of operating anelectrical power distribution system, such as power distribution system100, comprising a plurality of circuit protection devices coupledbetween an electrical power source and a plurality of electrical loads.Each circuit protection device of the plurality of circuit protectiondevices include a trip unit, a network interface communicatively coupledto a communication network including the plurality of circuit protectiondevices, a processor, and a memory.

At 802 one of the circuit protection devices transmits identificationdata to the other circuit protection devices of the plurality of circuitprotection devices over the communication network. The identificationdata can include information such as a unique identifier of thetransmitting circuit protection device, functional capabilities of thetransmitting circuit protection device, identification of a loadconnected to the transmitting circuit protection device, an electricalposition (e.g., upstream/downstream) of the transmitting circuitprotection device, what type of device that the transmitting circuitprotection device is, and/or operational settings of the transmittingcircuit protection device. The one of the circuit protection devicesreceives, at 804, identification data from the other circuit protectiondevices of the plurality of circuit protection devices over thecommunication network. At 806, the one of the circuit protection devicesstores the identification data from the other circuit protection devicesin its memory. In some embodiments, the receiving circuit protectiondevice determines an approximation of its physical proximity to theother circuit protection and stores the approximation in its memory.

Connecting circuit protection devices 106 in a communication network insystem 100 permits a significant amount of information to becommunicated between circuit protection devices 106. This informationenables circuit protection devices 106 to operate based on a morecomplete picture of the overall operation and conditions of powerdistribution system 100. In the example embodiment, for example, circuitprotection devices 106 are enabled to perform intelligent zone selectiveinterlocking (ZSI) based on data beyond a simple ZSI restraining signal.In some embodiments, circuit protection devices 106 do not output a ZSIrestraining/blocking signal.

Generally, circuit protection devices, such as circuit protection device106, use ZSI to prevent upstream circuit protection device 106 fromtripping due to an excessive current (or other fault condition) when adownstream circuit protection device 106 has detected the current andshould trip to interrupt the electrical current. The ZSI threshold istypically less than the tripping threshold at which the downstreamcircuit protection device 106 trips. In response to receiving a blockingsignal, the upstream circuit protection device 106 may shift from anunrestrained mode of operation to a restrained mode of operation, toprevent the upstream and downstream circuit protection devices 106 fromoperating at similar trip timing sequences. Additionally oralternatively, the upstream circuit protection device 106 may switch tooperating at, or using, a higher trip threshold, such as switching froma protective threshold to a backup threshold, in response to receiving ablocking signal from a downstream circuit protection device 106.

In some embodiments, in an unrestrained mode of operation, anunrestrained trip timing sequence may be executed that includesaccumulating time values in which the current exceeds the protectivethreshold until an unrestrained time threshold is reached. In therestrained mode of operation, a restrained trip timing sequence may beexecuted that includes accumulating time values in which the currentexceeds the backup threshold until a restrained time threshold isreached. If the restrained time threshold or the unrestrained timethreshold is reached, circuit protection device 106 trips.Alternatively, the unrestrained trip timing sequence and the restrainedtrip timing sequence may include any other actions or responses thatenable circuit protection devices 106 to function as described herein.It should be recognized that the unrestrained trip timing sequencecauses a trip signal to be generated in a period of time that is shorterthan a period of time in which the restrained trip timing sequencecauses a trip signal to be generated.

The restrained mode of operation may reduce the risk of an upstreamcircuit protection device 106 tripping before a downstream circuitprotection device during a downstream fault, also referred to as a“nuisance trip”. If the upstream circuit protection device 106 tripsbefore the downstream circuit protection device 106, other downstreamcircuit protection devices 106 coupled to the upstream circuitprotection device 106 are interrupted and current will not flow to anyloads coupled to such downstream circuit protection devices 106.

In the example embodiment, when a circuit protection device's monitoredelectrical current exceeds a ZSI threshold (also referred to sometimesas a “blocking threshold”), the circuit protection device 106 sends ZSIdata formatted according to the appropriate communication protocol toother circuit protection devices 106 over the communication network. Insome embodiments, circuit protection device 106 transmits the ZSI datato all other circuit protection devices 106 in system 100. In otherembodiments, each circuit protection device 106 knows its hierarchicalrelationship to the other circuit protection devices 106 transmits theZSI data only to those circuit protection devices 106 located upstreamfrom the transmitting circuit protection device 106.

In the example embodiment, the ZSI data includes at least anidentification of which circuit protection device 106 is transmittingthe ZSI data and an indication that the transmitting circuit protectiondevice 106 has detected a current exceeding its ZSI threshold. In someembodiments, the ZSI data also includes an amount of electrical currentsensed by the transmitting circuit protection device 106. In otherembodiments, the ZSI data includes a value of the current signalmeasured by the transmitting circuit protection device's current sensor,which the receiving circuit protection device 106 converts to an amountof current based on data about the transmitting circuit protectiondevice 106. The ZSI data may also include an indication of the locationof the transmitting circuit protection device 106 within system 100. Forexample, the location indication may include a level within thehierarchy of system 100, and/or an identification (such as a name, loadtype, identification number, etc.) of which load 104 is served by thetransmitting circuit protection device 106. In some embodiments, the ZSIdata includes an operational mode in which the transmitting circuitprotection device 106 is currently operating. The operational mode maybe one of a plurality of operational modes stored in memory 140. Eachoperational mode will typically include one or more settings, such aspickup thresholds, calibration factors, and the like. Exampleoperational modes include a standard mode, a restrained mode, and amaintenance mode. In some embodiments, the ZSI data includesidentification of one or more specific settings currently active in thetransmitting circuit protection device 106. ZSI data may also include anintended action to be taken by the transmitting circuit protectiondevice 106. For example, the ZSI data may include an indication that thetransmitting circuit protection device 106 intends to trip immediately,intends to trip if the present electrical current remains the same for aspecified time, intends to trip according to a particular predefinedsetting, intends to trip immediately if the electrical current increasesabove the present value, etc. In some embodiments, the ZSI data includesa percentage of the trip threshold of the transmitting circuitprotection device, an expected/predicted time to trip or clear adetected fault, a type of pickup (e.g., a ground fault or a short time),or any other data suitable for use in a zone selective interlockingsystem.

In the example embodiment, each circuit protection device 106 receivesoperational data (sometimes referred to herein as “additional data”)from all or a portion of the other circuit protection devices 106 insystem 100. The additional data can include electrical currents sensedby the other circuit protection devices 106, the present status andoperational modes of the other circuit protection devices 106, thelocation of the other circuit protection devices within the hierarchy ofsystem 100, temperature measurements from other circuit protectiondevices 106, etc. Accordingly, when a circuit protection device 106receives ZSI data from another circuit protection device 106, thereceiving circuit protection device 106 is able to determine how toreact to the ZSI data based on the ZSI data, its own operational data(e.g., its sensor data and present operational mode), and additionaldata received from other circuit protection device 106 rather thanslavishly responding to a ZSI blocking signal.

Thus, for example, if an upstream circuit protection device 106 receivesZSI data from a downstream circuit protection device 106, the upstreamcircuit protection device 106 may analyze the ZSI data, the current thatthe upstream circuit protection device 106 is sensing, the currentssensed by other circuit protection devices 106 as presented in theadditional data, and any other relevant additional data to determinewhether the potential problem detected by the downstream circuitprotection device 106 is the only problem in system 100 and whether ornot the transmitting downstream circuit protection device 106 is capableof satisfactorily handling the potential problem. If the upstreamcircuit protection device 106 determines that the downstream circuitprotection device 106 is able to handle the problem and there are noother problems, the upstream circuit protection device 106 may switch toa restrained mode of operation. Alternatively, if the upstream circuitprotection device 106 determines that there may be another problem withsystem 100, such as by detecting an electrical current larger thanshould be seen based on the ZSI data and the additional data, theupstream circuit protection device 106 may decline to switch to therestrained operational mode. Instead, the upstream circuit protectiondevice 106 may remain in its current operational mode, immediately trip,switch to a more sensitive (e.g., quicker tripping) operational mode, ortake any other suitable action. Similarly, if the upstream circuitprotection device 106 receives ZSI data from more than one downstreamcircuit protection device 106 within a relatively small period of time,the upstream circuit protection device 106 may decline to switch to therestrained operational mode and may remain in its current operationalmode, immediately trip, switch to a more sensitive operational mode, ortake any other suitable action. Moreover, the upstream circuitprotection device 106 may check the relative positions of the two ZSItransmitting circuit protection devices 106 before acting on the ZSIdata. If, for example, the two ZSI transmitting circuit protectiondevices 106 are serving the same load, the upstream circuit protectiondevice 106 may determine to switch to the restrained operational mode,if it does not detect any other problems with system 100.

In some embodiments, the circuit protection device 106 has more optionsfor how to respond to received ZSI data than would typically be found inmany known systems. As mentioned above, the receiving circuit protectiondevice 106 may remain in its present operational mode, switch to therestrained mode, immediately trip, or switch to some other operationalmode. Additionally, there may be multiple levels of operational modesthat are generally categorized under a heading of standard orrestrained. For example, a circuit protection device 106 may havemultiple restrained operational modes, each of which is more restrainedthan the standard mode, but each of which has somewhat differentcharacteristics from each other restrained mode. Thus, the circuitprotection device 106 can provide a response more finely tuned to theparticular circumstances and/or the particular conditions of system 100as a whole than would be available if the only options were standard andrestrained modes. In embodiments in which circuit protection devices 106transmit predicted time to trip or clear a fault as part of the ZSIdata, the circuit protection device 106 that receives the ZSI data mayadjust how long it remains in a restrained operation mode based thepredicted time to trip. Similarly, when the type of pickup is part ofthe ZSI data, the receiving circuit protection device 106 may determinenot to switch to the restrained operation mode if detected fault typesdo not match.

After a circuit protection device 106 receives ZSI data from anothercircuit protection device 106 and determines how to react to thereceived ZSI data, the receiving circuit protection device 106, in someembodiments, sends a communication to one or more of circuit protectiondevices 106. The communication may include its intended action, itspresent operational mode, the electrical current it is currentlysensing, or any other relevant information. Moreover, the receivingcircuit protection device 106 may retransmit the ZSI data to othercircuit protection devices 106 that may not have received the ZSI datafrom the original source.

FIG. 9 is a flow diagram of an example method 900 of operating anelectrical power distribution system. The electrical power distributionsystem includes a plurality of circuit protection devices coupledbetween an electrical power source and a plurality of electrical loads.Each circuit protection device of the plurality of circuit protectiondevices comprising a network interface communicatively coupled to acommunication network including the plurality of circuit protectiondevices, a processor, and a memory device. For convenience, method 900will be discussed with reference to system 100 and the components ofsystem 100 (all shown in FIG. 1). It should be understood, however, thatmethod 900 may be used with any other suitable electrical powerdistribution system.

The method 900 includes receiving, by a first circuit protection device114 of the plurality of circuit protection devices 106, zone selectiveinterlocking (ZSI) data from at least a second circuit protection device120 downstream from the first circuit protection device 114. The ZSIdata is formatted according to a network communication protocol of thecommunication network.

At 904, first circuit protection device 114 determines whether to changean operational mode of the first circuit protection device 114 to arestrained operational mode based, at least in part, on the received ZSIdata from downstream circuit protection device 120.

In some embodiments, of circuit protection devices 106 coordinate toprovide maintenance mode protection in system 100. Generally, when amaintenance mode operational setting of one circuit protection device106 is enabled (i.e. its operational mode is switched from its presentmode to the maintenance mode), all circuit protection devices 106 thatare located physically close to the maintenance mode enabled circuitprotection device 106 also switch to a maintenance mode operationalsetting.

To accomplish coordinated maintenance mode protection, circuitprotection devices 106 are configure, such as by instructions stored inmemory 140, to determine the physical distance between circuitprotection devices 106. The physical distance represents how closecircuit protection devices 106 are physically located to each other,rather than the electrical relationship between circuit protectiondevices 106. While circuit protection devices 106 that are electricallyclose may also be physically close, it is not required. Circuitprotection devices 106 that are electrically distant (or even unrelated)may be housed in a same switchgear unit. Conversely, circuit protectiondevices 106 that are electrically close, such as circuit protectiondevices 106 fed by a same feeder circuit protection devices 106 may bedisposed in separate switchgear units.

In the example embodiment, the physical distance of a circuit protectiondevice 106 from another circuit protection device is determined based atleast in part on a characteristic of a network communication signal sentby one of the two circuit protection devices 106 and received by theother circuit protection device 106. The characteristic can be anysuitable characteristic of the network communication signal for whichcan be analyzed to determine an approximation of the physical distancethat the network communication signal was sent. The approximation of thedistance the signal was sent is used as an approximation of the distancebetween the sending and receiving circuit protection devices 106.

For example, if a network communication signal is transmitted wirelesslybetween two circuit protection devices 106, the wireless signal strengthof the network communication signal received by a second of the circuitprotection devices 106 from a first of the circuit protection devices106 may be used to determine an approximation of the distance betweenthe first of the circuit protection devices 106 and the second of thecircuit protection devices. By comparison of the signal strength of thereceived network communication signal to the actual or predicted signalstrength of the network communication signal when transmitted, theapproximate distance between the circuit protection devices 106 may beestimated. The signal strength may be converted to an approximatedistance measurement, converted to a percentage, and/or used withoutconversion. Similarly, in a wired network configuration of system 100,the attenuation of the wired network communication signal may be used todetermine an approximation of the distance between transmitting andreceiving circuit protection devices 106.

In the example embodiment, the physical locations of circuit protectiondevices 106 relative to each other are initially mapped by circuitprotection devices 106 when system 100 is installed. In someembodiments, the physical locations of circuit protection devices 106relative to each other are mapped by circuit protection devices 106periodically (e.g., every time a network communication is received,daily, weekly, monthly, on demand, etc.). In some embodiments thephysical locations of circuit protection devices 106 relative to eachother are mapped by circuit protection devices 106 upon occurrence of atriggering event, such as upon receipt of a message indicating amaintenance mode is enabled for a circuit protection device 106.

Each circuit protection device 106 stores an indication of itsapproximate distance from each other circuit protection device 106 inits memory 140. The indication may be a computed distance, a signalattenuation level, one or more groupings of circuit protection devices106 by relative degrees of closeness, or any other data suitable forindicating a degree of closeness of circuit protection devices 106 toeach other. For example, all circuit protection devices 106 that areless than a first threshold distance away (or that have a signalstrength greater than a threshold value) may be identified in a firstgroup and the remaining circuit protection devices 106 may be identifiedin a second group. The first group are circuit protection devices 106that are physically close, while the second group includes circuitprotection devices 106 that are more distant. Of course, more than twogroups and more than one threshold may be used to group circuitprotection device 106.

When maintenance is to be performed on or in the vicinity of a circuitprotection device 106, that circuit protection device is typically placein a maintenance mode. In the maintenance mode, the circuit protectiondevice's settings are adjusted to make it more sensitive to undesiredcurrent levels and, if possible, decrease the amount of time needed toreact to an undesired current level. Thus, circuit protection device 106is easier and/or quicker to trip when the maintenance mode is enabled.In some embodiments, maintenance mode is enabled by a user manuallyenabling the maintenance mode, such as using a switch, a button, a userinterface on or near the circuit protection device 106, or using aremote communication device, such as laptop computer 212 or smartphone214.

In other embodiments, maintenance mode is automatically enabled for oneor more circuit protection devices 106. Maintenance mode may beautomatically enabled based on one or more sensors detecting a humanbody within a predefined proximity of one of circuit protection devices106.

FIG. 10 is a simplified diagram of a portion 1000 of system 100configured for use with manual and/or automatic maintenance modeenablement combined with coordinated maintenance mode protection. Inthis embodiment, circuit protection devices 106 are disposed inswitchgear units 1002, 1004, and 1006 in a room 1007. Sensors 1008,1010, and 1012 are configured to detect the location of a body relativeto switchgear units 1002, 1004, and 1006. Sensors 1008 detect when anoperator is accessing circuit protection devices 106 and/or an interiorof switchgear unit 1002, 1004, and 1006. The sensors 1008, 1010, and1012 may be motion detectors, pressure sensors, thermal sensors, doorsensors, or any other suitable sensor for detecting when a body may benear circuit protection devices 106 and/or preparing to access circuitprotection devices 106. Sensor 1008 may be, for example, door sensorsthat detect when doors (not shown) to the interior of switchgear units1002, 1004, and 1006 are opened. Additionally, or alternatively, sensors1008 may be sensor within switchgear units 1002, 1004, and 1006 thatdetect access or movement of circuit protection devices 106. Sensor 1012detects when a body is entering room 1007 and may be, for example a doorsensor attached to a door (not shown) that provides access to room 1007.Sensor 1010 detects when a body is located within an arc flash zone1014. Arc flash zone 1014 is defined around switchgear unit 1002. Forclarity, the arc flash zones that would be defined around switchgearunits 1004 and 1006 are not shown. Generally, arc flash zones 1014 arezones in which there may be a risk of injury to a body located in thezone if an arc flash occurred in the switchgear unit that defines thezone. Moreover, in some embodiments, maintenance mode may beautomatically enabled for a circuit protection device based on detectionof a user's remote communication device in proximity to that circuitprotection device 106. For example, if a user's laptop computer 212wirelessly connects to a circuit protection device 106 using arelatively short-range communication protocol, maintenance mode may beenabled for that circuit protection device 106. Maintenance mode may,additionally or alternatively, be manually enabled by an operator.

Whether automatically or manually enabled, when a circuit protectiondevice 106, such as a first circuit protection device 1016, is switchedto the maintenance mode, the other circuit protection devices 106selectively switch to maintenance mode based at least in part onproximity to the maintenance mode enabled circuit protection device 106and the maintenance status of first circuit protection device 1016. Insome embodiments, the other circuit protection devices 106 detect themaintenance status of first circuit protection device. In otherembodiments, the other circuit protection devices receive a maintenancestatus message from first circuit protection device 1016 through thecommunication network. The maintenance status message is transmitted toall circuit protection devices communicatively coupled to thecommunication network of system 100. Alternatively, the maintenancestatus message may be transmitted to a subset of all circuit protectiondevices 106. The subset includes only those circuit protection devicesthat are less than a threshold distance away from first circuitprotection device 1016.

However the maintenance status of circuit protection device is detectedby the other circuit protection devices 106, they determine whether ornot to switch to the maintenance mode based in part on their distancefrom first circuit protection device 1016. In embodiments in which themaintenance message is transmitted only to the subset of circuitprotection devices 106 that are less than the threshold distance fromfirst circuit protection device 1016, all circuit protection devices 106that receive the message know they are close to first circuit protectiondevice 1016 without any additional analysis being needed. In embodimentsin which circuit protection devices 106 detect the maintenance status offirst circuit protection device 1016 or in which all circuit protectiondevices 106 receive the maintenance message, each circuit protectiondevice 106 determines how close it is to first circuit protection device1016. More particularly, each circuit protection device 106 determinesif it is less than the threshold distance from first circuit protectiondevice 1016. The determination may be made based on a characteristic ofthe maintenance message, a characteristic of previous data messagesreceived from first circuit protection device 1016, previously provideddistance data, data contained in the maintenance message, or based onany other suitable method.

In the example embodiment, the threshold distance is a distance fromfirst circuit protection device 1016 to a boundary 1018 of arc flashzone 1014. Thus, any circuit protection device 106 within arc flash zone1014 is also within the threshold distance from first circuit protectiondevice 1016. In FIG. 10, circuit protection devices 106 withinswitchgear units 1002 and 1004 are within arc flash zone 1014 and lessthan the threshold distance from first circuit protection device 1016.Circuit protection devices 106 in switchgear unit 1006 are outside arcflash zone 1018 and their distance from first circuit protection device1016 equals or exceeds the threshold distance. In other embodiments, thethreshold distance may be any other suitable threshold distance. Forexample, the threshold distance may be based on a size of room 1007,such that all circuit protection devices 106 within room 1007 are lessthan the threshold distance from all other circuit protection devices inroom 1007. In such an embodiment, circuit protection devices 106 outsideof room 1007 would not be less than the threshold distance from circuitprotection devices 106 within room 1007.

Upon determining, by whichever method, that the first circuit protectiondevice's maintenance status includes being switched to maintenance mode,the particular circuit protection devices 106 that are spaced from firstcircuit protection device 1016 by less than the threshold distanceselectively enable their own maintenance mode. In the exampleembodiment, circuit protection devices 106 that determine they arespaced from first circuit protection device 1016 by less than thethreshold distance will enable their maintenance mode in response to thedetection of first circuit protection device 1016 having its maintenancemode enabled. Because circuit protection device 106 are communicativelycoupled together and receive operational data from multiple circuitprotection devices 106, one or more circuit protection device maydetermine, in some embodiments, not to enable its protection mode due tosome other condition in system 100 that takes precedence over switchingto the maintenance mode. Similarly, one or more circuit protectiondevice may determine, based on a condition that exists in system 100, totrip in response rather than switching to the maintenance mode.

Circuit protection devices 106 that are further away from first circuitprotection device 1016 than the threshold distance continue to operateaccording to their present operating mode after determining that firstcircuit protection device 1016 has had its maintenance mode enabled. Insome embodiments, such distant circuit protection devices 106 may altertheir settings to a somewhat more sensitive setting, enable theirmaintenance operation modes, or take any other suitable protectiveaction based on first circuit protection device 1016 being inmaintenance operation mode and, for example, detection of some othercondition in system 100 that indicates extra caution/protection may bedesired.

Moreover, in some embodiments, one or more non-circuit breaker circuitprotection devices (not shown) in system 100 may be enabled in responseto maintenance mode enablement of first circuit protection device 1016.For example, an arc flash containment device near first circuitprotection device 1016 may be enabled in response to receiving amaintenance message from first circuit protection device 1016.Alternatively, another of circuit protection devices 106 may instructthe arc flash containment device to enable itself when that circuitprotection device determines that first circuit protection device 1016is operating in the maintenance mode.

In some embodiments, multiple threshold distances defining multiplezones of proximity to first circuit protection device 1016 may be used.Different actions may be taken based at least in part on in which zoneof proximity to first circuit protection device 1016 a particularcircuit protection device 106 is located. In FIG. 10, for example, thedistance from first circuit protection device 1016 to boundary 1018 maydefine a first threshold distance, while a distance from first circuitprotection device 1016 to a boundary 1020 (e.g., a wall) of room 1007may be used as a second threshold distance. The first threshold distancedefines the arc flash zone around first circuit protection device 1016and the second threshold distance approximately defines an in-room zonearound first circuit protection device 1016. In multiple thresholdembodiments, circuit protection devices 106 may take different actionsbased on which zone each circuit protection device 106 is locatedwithin. For example, circuit protection devices 106 in switchgear units1002 and 1004 are closer than the first threshold distance (i.e., withinarc flash zone 1014) and switch to their maintenance mode. The distancebetween circuit protection devices 106 in switchgear unit 1006 and firstcircuit protection device 1016 is less than the second thresholddistance but greater than or equal to the first threshold distance(i.e., they are within room 1007, but not within arc flash zone 1014).Accordingly, circuit protection devices 106 in switchgear unit 1006 mayswitch to an operational mode that is more sensitive/faster than theirstandard operational setting, but less sensitive/slower than themaintenance mode that is enabled on circuit protection devices 106 inswitchgear units 1002 and 1004.

FIG. 11 is a flow diagram of an example method 1100 of coordinatingmaintenance modes in an electrical power distribution system, such assystem 100. The electrical power distribution system, includes aplurality of circuit protection devices. Each circuit protection deviceincludes a network interface communicatively coupled to a communicationnetwork including the plurality of circuit protection devices, aprocessor, and a memory device. The method includes, at 1102,transmitting, by each circuit protection device of the plurality ofcircuit protection devices, a network communication signal to thecommunication network. The approximate physical distances between thecircuit protection devices is determined 1104 based at least in part ona characteristic of the network communication signals transmitted byeach circuit protection device. A maintenance mode of each circuitprotection device of a subset of the circuit protection devices isenabled 1106 in response to enablement of a maintenance mode of onecircuit protection device of the plurality of circuit protectiondevices. The subset of the circuit protection devices is determined atleast in part by the approximate physical distance of the circuitprotection devices from the maintenance mode enabled one circuitprotection device.

In some embodiments, coordinated ground fault detection is provided bysystem 100. In such embodiments, circuit protection devices 106 sharetheir detected current data with one or more other circuit protectiondevices 106. The circuit protection devices 106 that receive the currentdata are operable, such as by instruction stored in memory device 140,to use the received current data to determine whether or not a groundfault condition exists in system 100.

FIG. 12 is a flow diagram of an example method 1200 of operating anelectrical power distribution system, such as system 100, withcoordinated ground fault detection. Method 1200 will be described withreference to system 100 and components of system 100. However, method1200 may be used with any suitable electrical power distribution system.

At 1202, each circuit protection device 106 of a plurality of circuitprotection devices 106 transmits an electrical current communication toa communication network. The electrical current communication includesan indication of an electrical current measured by the circuitprotection device 106 using a current sensor 134. using a current sensor134. The electrical current communication is a formatted according tothe network protocol of the communication network to which circuitprotection devices 106 are coupled.

In the example embodiment, each circuit protection device 106 transmitsits electrical current communication to only one circuit protectiondevice 106 that will act as a decision maker, with respect to groundfault detection, for circuit protection devices 106. In otherembodiments, each circuit protection device 106 transmits its electricalcurrent communication to all other circuit protection devices 106 andany or all of the circuit protection devices 106 may perform the furthersteps of method 1200 discussed below.

The indication of the electrical current included in the electricalcurrent communication is determined by each circuit protection device106 from a current signal received from its current sensor 134. In someembodiments, each circuit protection device 106 converts the currentsignal into an amount of detected current and includes the amount ofdetected current in the electrical current communication. In otherembodiments, the value of the current signal is included in theelectrical current communication and the receiving circuit protectiondevice 106 converts the value of the current signal into the amount ofdetected current.

To determine whether or not a ground fault condition exists, theelectrical current for each circuit protection device should be measuredat the same time. In some embodiments, the time for current detection isbased on an clock signal within each circuit protection device 106. Inother embodiments, the time is determined based on a synchronizationsignal. The synchronization signal may be transmitted to circuitprotection devices 106 by one of circuit protection devices 106 or byany other suitable component. In some embodiments, the particularcircuit protection device 106 that will act as a decision maker forground fault detection transmits the synchronization signal. In someembodiments, the particular circuit protection device 106 transmits arequest for the electrical current communication to the other circuitprotection devices 106. In response to the receipt of the request, eachreceiving circuit protection device 106 detects its current at the timeof receipt, thus allowing the request to function as a synchronizationsignal.

At 1204, an additional circuit protection device 106 receives theelectrical current communications from the plurality of circuitprotection devices 106. As discussed above, each circuit protectiondevice 106 may function as the additional circuit protection device or asingle circuit protection device 106 may be designated to function asthe additional circuit protection device 106.

The additional circuit protection device 106 determines, at 1206 andbased on the received electrical current communications, whether aground fault condition exists in the electrical power distributionsystem. A ground fault is identified by summing the values of thecurrents received in the electrical current communications. If the sumof the values is zero, there is no ground fault. If the sum does notequal zero, a ground fault condition exists. In multi-phase systems, thesumming may include calculating a vector sum of the current in eachelectrical phase in system 100. In other embodiments, any suitablemethod for detecting a ground fault based on current measurements fromcircuit protection devices 106 may be used.

In some embodiments, method 1200 includes tripping a trip unit tointerrupt electrical current in electrical power distribution system 100in response to the additional circuit protection device 106 determiningthat a ground fault condition exists in system 100. If the additionalcircuit protection device 106 is located electrically upstream from thedetected ground fault condition, the additional circuit protectiondevice 106 may trip its own circuit protection device. In someembodiments, the additional circuit protection device 106 transmits atrip command to another circuit protection device 106 to cause it totrip its trip unit. The target of the trip command may be predetermined,such as the most upstream circuit protection device 106 in system 100.In other embodiments, the target of the trip command may be determinedat the time of ground fault condition detection. For example, the targetof the trip command may be based on the location of the ground faultcondition. In such an embodiment, the additional circuit protectiondevice 106 determines what portion of system 100 is affected by theground fault condition, determines one or more circuit protectiondevices 106 that protect the determined portion, and transmits a tripcommand to each of the circuit protection devices 106 that protect thedetermined portion.

In at least some embodiments, the power distribution systems describedherein are configured to facilitate testing and/or simulation ofelectrical conditions within the power distribution systems. Morespecifically, each circuit protection device and/or other componentwithin the power distribution system receives test data representing anelectrical condition and generates response data (e.g., circuitprotection data) representing a simulated response of the device. Asused herein, “simulating” electrical conditions and responses to suchconditions refers to the circuit protection devices analyzing the testdata associated with the electrical condition using the same orsubstantially similar process as measured data. However, unlike measureddata, the circuit protection devices do not actually change theiroperational parameters (e.g., trip riming sequence, operational mode,etc.) or cause a trip unit to interrupt current when simulating aresponse. Rather, the response data indicates what test data the circuitprotection device received and the changes that would have been made inresponse to the test data. The response data is aggregated at asystem-level using a communication network to facilitate system-levelanalysis of the power distribution system for the tested electricalcondition. The analysis is repeatable for a plurality of electricalconditions. System-level analysis for a plurality of electricalconditions facilitates reduced testing time in comparison to previoustesting systems for power distribution systems. In these testingsystems, each circuit protection device is manually and individuallytested, which may be a time-consuming process that potentially delaysthe normal operation of the power distribution system.

As used herein, an “electrical condition” refers to parameters andinstructions that affect the electrical response of the powerdistribution system. In one example, a fault within the powerdistribution system is an electric condition. In another example, amaintenance mode for circuit protection devices that adjusts theelectrical response of the circuit protection devices is an electricalcondition. The electrical condition may be represented as set ofpredetermined voltage, current, and/or power values. Additionally oralternatively, the electrical condition may be represented as one ormore commands or instructions received by the circuit protection devicesin the power distribution system. In at least some embodiments, duringsetup of the electrical power distribution system, the system is testedfor a plurality of electrical conditions to ensure the system isconfigured to operate properly. These tests may be repeated periodicallyduring operation to proactively detect problems developing within thesystem such that the problems may be addressed prior to the actualelectrical condition occurring.

FIG. 13 is a data flow diagram of an exemplary power distribution system1300 for testing the response of system 1300 to various electricalconditions. In the exemplary embodiment, system 1300 is similar to powerdistribution system 100 (shown in FIG. 1), and in the absence ofcontrary representation, system 1300 includes similar components. Thatis, system 1300 includes a plurality of circuit protection devices 1306electrically coupled together through distribution bus 1308. In otherembodiments, system 1300 includes a different number of circuitprotection devices 1306 in a different configuration (e.g., theconfiguration shown in FIG. 1). Circuit protection devices 1306 arecommunicatively coupled to each other within a communication network1350 as described herein. Each circuit protection device 1306 includesan integrated trip unit 1332, a sensor 1334, and a trip mechanism 1336.Trip unit 1332 includes a processor 1338 coupled to a memory 1340, aninput device 1342, a display device 1344, and a network interface 1346.In other embodiments, system 1300 and/or circuit protection device 1306may include additional, fewer, or alternative components, includingthose described elsewhere herein.

At least one of circuit protection devices 1306 is communicativelycoupled to a remote access device 1352. Remote access device 1352 is acomputing device that enables a user to monitor data from circuitprotection device 1306. In some embodiments, remote access device 1352is communicatively coupled to communication network 1350. In otherembodiments, remote access device 1352 is communicatively coupled to oneor more circuit protection devices 1306 using a different communicationnetwork. Circuit protection devices 1306 are configured to generate,transmit, and receive circuit protection data 1354 (also sometimesreferred to as “operational data”). Circuit protection data 1354includes one or more parameters, instructions, notifications, and/orother data associated with circuit protection devices 1306.

To test system 1300 for a particular electrical condition, remote accessdevice 1352 is configured to generate a test message 1356 and transmittest message 1356 to one or more circuit protection devices 1306. Testmessage 1356 includes test data 1358 that represents or simulates theelectrical condition. That is, test data 1358 includes one or moreelectrical parameters or control signals that simulate the electricalcondition. For example, to simulate a fault condition in system 1300,test data 1358 includes current data that, when measured by circuitprotection device 1306 near the simulated fault condition, would causetrip unit 1332 to trip. In at least some embodiments, test message 1356further includes a test identifier 1360. Test identifier 1360 indicatesto circuit protection devices 1306 that test data 1358 is associatedwith a test or simulation. Test identifier 1360 enables circuitprotection devices 1306 to differentiate between measured data and testdata 1358. In certain embodiments, during standard operation of system1300, circuit protection devices 1306 are configured to operate andrespond to measured data in parallel to testing responses to electricalconditions, thereby facilitating testing without interrupting operationof system 1300. In some embodiments, test message 1356 is generated bycircuit protection device 1306. For example, in one embodiment, remoteaccess device 1352 may transmit an initial test message 1356 to circuitprotection devices 1306 for a recurring test such that subsequent testmessages 1356 are generated by at least one circuit protection device1306.

Circuit protection devices 1306 are configured to respond to test data1358 similar to measured data (e.g., measured current data) from system1300. That is, circuit protection devices 1306 receive test data 1358,analyze test data 1358 for any electrical conditions and/or commandinstructions, and generate circuit protection data 1354 based on theanalysis. Circuit protection data 1354 includes metadata similar to testidentifier 1360 that identifies circuit protection data 1354 asassociated with test message 1356. In the exemplary embodiment, circuitprotection data 1354 includes data associated with, for example and notlimited to, “measured” electrical parameters, trip responses,operational modes (e.g., maintenance mode), ZSI data, and/or deviceparameters, such as trip timing sequences.

However, unlike the measured data, test data 1358 does not cause, forexample, trip unit 1332 to trip or circuit protection device 1306 toswitch operating modes (e.g., to a maintenance mode). More specifically,circuit protection device 1306 simulates a response to test data 1358without changing the present operation of circuit protection device.1306. For example, circuit protection data 1354 may include trip datathat includes an electric current value, a voltage value, a power value,a trip timing sequence, and/or other data element associated with asimulated trip response of trip unit 1332.

In the exemplary embodiment, circuit protection devices 1306 areconfigured to store a set of test operational parameters 1362. The testoperational parameters 1362 represent the operation of circuitprotection devices 1306, and may include measured current data, triptiming sequences, trip thresholds, ZSI thresholds, operational modes,and/or the like. Test operational parameters 1362 do not affect theactual operation of circuit protection devices 1306, but rather affectthe simulated responses of circuit protection devices 1306 to test data1358 and circuit protection data 1354. Test operational parameters 1362may reset for each test performed by system 1300. Additionally oralternatively, separate test operational parameters 1362 are generatedand stored for each test. In certain embodiments, test operationalparameters 1362 are defaulted to the actual operating parameters ofcircuit protection devices 1306 at the time of the test. In at leastsome embodiments, at least some test operational parameters are includedin circuit protection data 1354.

Circuit protection data 1354 is transmitted to other circuit protectiondevices 1306 and/or remote access device 1352. In some embodiments,circuit protection device 1306 that generated circuit protection data1354 adds circuit protection data 1354 to test message 1356 andtransmits test message 1356 to another circuit protection device 1306.If circuit protection data 1354 is transmitted to other circuitprotection devices 1306 through network 1350, the other circuitprotection devices 1306 are configured to generate additional circuitprotection data based at least partially on circuit protection data1354. For example, as described herein, if a first circuit protectiondevice 1306 identifies a fault, the first protection device 1306includes a ZSI signal in circuit protection data 1354 and transmits data1354 to an upstream circuit protection device 1306. The upstream circuitprotection device 1306 detects the ZSI signal and simulates adjustingits trip timing sequence based on the detected ZSI signal.

In the exemplary embodiment, circuit protection data 1354 from circuitprotection devices 1306 is aggregated within a simulation log 1364.Simulation log 1364 facilitates a system-level analysis of circuitprotection data 1354. In at least some embodiments, simulation log 1364includes a device identifier and timestamp for each response event(e.g., a trip response, a ZSI signal, etc.) to enable timing analysis ofcircuit protection data 1354. Simulation log 1364 may also include testdata 1358 to indicate which electrical condition was tested. In theexemplary embodiment, access device 1352 is configured to collectcircuit protection data 1354 and generate simulation log 1364 foranalysis. In other embodiments, simulation log 1364 may be generated bycircuit protection devices 1306 as circuit protection data 1354 isgenerated in response to test message 1356. In one example, simulationlog 1364 is transmitted to each circuit protection device 1306 such thatsimulation log 1364 is updated with circuit protection data 1354 at eachcircuit protection device 1306.

Remote access device 1352 is configured to facilitate system-levelanalysis of circuit protection data 1354 and/or simulation log 1364 tomonitor the response of circuit protection devices 1306 to the testedelectrical condition. Unlike some known testing systems thatindividually test each circuit protection device 1306, simulation log1364 facilitates analysis of the interaction between circuit protectiondevices 1306 and identifying any issues with multiple circuit protectiondevices 1306 simultaneously. In at least some embodiments, remote accessdevice 1352 is configured to display simulation log 1364 and/or circuitprotection data 1354 to a user (not shown) to enable the user to performthe system-level analysis. In certain embodiments, remote access device1352 and/or circuit protection devices 1306 may analyze simulation log1364 and/or circuit protection data 1354 to detect any potential errors,warnings, or other issues within the data.

In certain embodiments, at least one circuit protection device 1306 isconfigured to analyze circuit protection data 1354 and/or simulation log1364 to generate a recommendation 1366. Recommendation 1366 indicates anadjustment within system 1300, such as adjusting one or more parametersof circuit protection device(s) 1306, that may improve the performanceof system and/or fixes a potential error in system 1300 (e.g.,miscalibrated circuit protection devices 1306). A user analyzesrecommendation 1366 to determine whether or not to apply the recommendedadjustment. In some embodiments, if a user approves recommendation 1366,system 1300 automatically applies the recommended adjustment. In oneembodiment, circuit protection devices 1306 are automatically calibratedwithout recommendation 1366.

FIG. 14 is a data flow diagram of power distribution system 1300 shownin FIG. 13 during exemplary testing for ZSI. More specifically, circuitprotection devices 1306 are tested to determine the trip response andtrip timing sequence for each circuit protection device 1306 during afault condition.

With respect to FIGS. 13 and 14, in the exemplary embodiment, whentesting ZSI in system 1300, test data 1358 includes data representing afault condition within system 1300. More specifically, test data 1358includes data representing a current exceeding a ZSI threshold at one ormore circuit protection devices 1306. When a first circuit protectiondevice 1306 determines test data 1358 includes a “measured” current atthe first circuit protection device 1306 exceeds the ZSI threshold, thefirst circuit protection device 1306 transmits test ZSI data 1402 to theother circuit protection devices 1306 through network 1350. In someembodiments, the first circuit protection device 1306 transmits test ZSIdata 1402 to one or more upstream circuit protection devices. Test ZSIdata 1402 is substantially similar or identical to the ZSI datatransmitted by circuit protection device 1306 when the actual measuredcurrent exceeds the ZSI threshold. Test ZSI data 1402 includes metadatathat indicates test ZSI data 1402 is associated with test data 1358 suchthat circuit protection devices 1306 that receive test ZSI data 1402 donot change switch operating modes in response. Rather, in someembodiments, circuit protection devices 1306 store test operationalparameters 1362 associated with test data 1358. In the exemplaryembodiment, test ZSI data 1402 is included in simulation log 1364.

Circuit protection devices 1306 analyze received test ZSI data 1402 anddetermine whether to simulate changing operational modes (e.g., anunrestrained mode to a restrained mode) based at least in part on theanalysis. If circuit protection devices 1306 simulate changing from afirst operational mode to a second operational mode, circuit protectiondata 1354 generated by the changed circuit protection devices 1306 andsimulation log 1364 indicate the operational mode change. The changedcircuit protection devices 1306 simulate responses to subsequentreceived test data 1358 and circuit protection data 1354 according tothe second operational mode. In one example, when a first circuitprotection device 1306 simulates switching to a restrained mode, thefirst circuit protection device 1306 simulates a restrained trip timingsequence for test data 1358 representing a measured current at the firstcurrent protection device 1306.

FIG. 15 is a data flow diagram of power distribution system 1300 shownin FIG. 13 during exemplary testing maintenance modes for circuitprotection devices. More specifically, circuit protection devices 1306are tested to simulate a maintenance condition. The maintenancecondition represents the physical presence of a maintenance worker orother user proximate to one or more circuit protection devices 1306.

With respect to FIGS. 13 and 15, in the exemplary embodiment, testmessage 1356 includes a maintenance mode instruction 1502. Maintenancemode instruction 1502 causes one or more circuit protection devices 1306to simulate switching to a maintenance mode. That is, circuit protectiondevices 1306 adjust stored test operational parameters without actuallyswitching to the maintenance mode such that circuit protection devices1306 analyzes and responds to subsequent test data 1358 based on theadjusted test operational parameters. Circuit protection devices 1306that simulate switching to the maintenance mode transmit a testmaintenance status message 1504 to at least a portion of circuitprotection devices 1306. Test maintenance status message 1504 issubstantially similar to the maintenance status message generated whencircuit protection device 1306 actually switches to the maintenancemode. Test maintenance status message 1504 includes metadata thatindicates test maintenance status message is associated with testmessage 1356. In the exemplary embodiment, test maintenance statusmessage 1504 is included in simulation log 1364.

In response to test maintenance status message 1504, circuit protectiondevices 1306 determine whether or not to simulate switching to themaintenance mode. In the exemplary embodiment, each circuit protectiondevice 1306 determines a physical distance between a first circuitprotection device 1306 in the maintenance mode and the particularcircuit protection device 1306. If the physical distance is within oneor more predetermined distance thresholds, circuit protection device1306 may simulate switching to the maintenance mode and transmit a testmaintenance status message 1504 to other circuit protection devices1306. If the physical distance exceeds the distance thresholds, circuitprotection devices 1306 may continue to operate according to theirpresent operating mode specified in the stored test operationalparameters. In some embodiments, rather than determining a physicaldistance, circuit protection devices 1306 identify a zone of proximityassociated with test maintenance status message 1504. If circuitprotection device 1306 is physically within the identified zone, circuitprotection device 1306 may simulate switching to the maintenance mode.

Exemplary embodiments of power distribution systems and methods ofoperating power distribution systems and/or circuit protection devicesare described above in detail. The systems and methods are not limitedto the specific embodiments described herein but, rather, components ofthe systems and/or operations of the methods may be utilizedindependently and separately from other components and/or operationsdescribed herein. Further, the described components and/or operationsmay also be defined in, or used in combination with, other systems,methods, and/or devices, and are not limited to practice with only thepower system as described herein.

The order of execution or performance of the operations in theembodiments of the invention illustrated and described herein is notessential, unless otherwise specified. That is, the operations may beperformed in any order, unless otherwise specified, and embodiments ofthe invention may include additional or fewer operations than thosedisclosed herein. For example, it is contemplated that executing orperforming a particular operation before, contemporaneously with, orafter another operation is within the scope of aspects of the invention.

Although specific features of various embodiments of the invention maybe shown in some drawings and not in others, this is for convenienceonly. In accordance with the principles of the invention, any feature ofa drawing may be referenced and/or claimed in combination with anyfeature of any other drawing.

This written description uses examples to disclose the invention,including the best mode, and also to enable any person skilled in theart to practice the invention, including making and using any devices orsystems and performing any incorporated methods. The patentable scope ofthe invention is defined by the claims, and may include other examplesthat occur to those skilled in the art. Such other examples are intendedto be within the scope of the claims if they have structural elementsthat do not differ from the literal language of the claims, or if theyinclude equivalent structural elements with insubstantial differencesfrom the literal language of the claims.

What is claimed is:
 1. An electrical power distribution systemcomprising: a plurality of circuit protection devices coupled between anelectrical power source and a plurality of electrical loads, eachcircuit protection device of the plurality of circuit protection devicescomprising: a trip unit configured to selectively trip to prevent a flowof electrical current through said circuit protection device; a networkinterface communicatively coupled to a communication network includingsaid plurality of circuit protection devices; a processor; and a memorystoring instructions that, when executed by said processor, cause saidprocessor to transmit, using said network interface, circuit protectiondevice data to the network, the circuit protection device data formattedaccording to a network communication protocol of the communicationnetwork.
 2. An electrical power distribution system in accordance withclaim 1, wherein the communication network comprises a wiredcommunication network.
 3. An electrical power distribution system inaccordance with claim 2, wherein said network interface of each circuitprotection device comprises a wired network interface connected to thewired communication network.
 4. An electrical power distribution systemin accordance with claim 2, further comprising a network bridgeconnected to the wired communication network, wherein said networkinterface of at least one circuit protection device of said plurality ofcircuit protection devices comprises a wireless network interfacewirelessly coupled to said network bridge.
 5. An electrical powerdistribution system in accordance with claim 4, wherein the networkbridge comprises a different circuit protection device, said differentcircuit protection device including a network interface connected to thewired communication network and wirelessly, communicatively coupled tosaid at least one circuit protection device.
 6. An electrical powerdistribution system in accordance with claim 2, further comprising awireless access point connected to the wired communication network. 7.An electrical power distribution system in accordance with claim 6,wherein said wireless access point comprises one circuit protectiondevice of said plurality of circuit protection devices.
 8. An electricalpower distribution system in accordance with claim 1, wherein thecommunication network comprises a wireless communication network andsaid network interface of each circuit protection device of saidplurality of circuit protection devices comprises a wireless networkinterface.
 9. An electrical power distribution system in accordance withclaim 8, wherein the wireless communication network comprises a meshnetwork and each circuit protection device of the plurality of circuitprotection devices is wirelessly, communicatively coupled to each othercircuit protection device of said plurality of circuit protectiondevices within range of its wireless network interface.
 10. Anelectrical power distribution system in accordance with claim 8, furthercomprising a network switch, said wireless network interface of eachcircuit protection device of said plurality of circuit protectiondevices communicatively coupled to said network switch to transmit thecircuit protection device data to the network through said networkswitch.
 11. An electrical power distribution system in accordance withclaim 10, wherein said network switch comprises one circuit protectiondevice of said plurality of circuit protection devices.
 12. Anelectrical power distribution system in accordance with claim 1, whereinthe network communication protocol comprises one of an Ethernetcommunication protocol and an IEEE 802.11 based communication protocol.13. An electrical power distribution system in accordance with claim 1,wherein said network interface of at least one circuit protection deviceof said plurality of circuit protection devices is operable forcommunicative coupling to an external non-circuit protection device. 14.A circuit protection device for an electrical distribution systemcomprising: a trip unit configured to selectively trip to prevent a flowof electrical current through said circuit protection device; a networkinterface configured for communicative coupling to a communicationnetwork; a processor; and a memory storing instructions that, whenexecuted by said processor, cause said processor to transmit, using saidnetwork interface, circuit protection device data to the network, thecircuit protection device data formatted according to a networkcommunication protocol of the communication network.
 15. A circuitprotection device in accordance with claim 14 wherein said networkinterface comprises a wireless network interface.
 16. A circuitprotection device in accordance with claim 15, further comprising awired network interface.
 17. A circuit protection device in accordancewith claim 14 wherein said network interface comprises a wired networkinterface.
 18. A method of operating an electrical power distributionsystem comprising a plurality of circuit protection devices coupledbetween an electrical power source and a plurality of electrical loads,each circuit protection device of the plurality of circuit protectiondevices comprising a trip unit, a network interface communicativelycoupled to a communication network including the plurality of circuitprotection devices, a processor, and a memory, said method comprising:transmitting, by one of the circuit protection devices, identificationdata to the other circuit protection devices of the plurality of circuitprotection devices over the communication network; receiving, by saidone of the circuit protection devices, identification data from theother circuit protection devices of the plurality of circuit protectiondevices over the communication network; and storing, by said one of thecircuit protection devices, the identification data from the othercircuit protection devices in its memory.
 19. A method in accordancewith claim 18, wherein transmitting, by one of the circuit protectiondevices, identification data to the other circuit protection devicescomprises transmitting identification data comprising at least one of aunique identifier of said one of the circuit protection devices,functional capabilities of said one of the circuit protection devices,and operational settings of said one of the circuit protection devices.20. A method in accordance with claim 18, further comprising:determining, by said one of the circuit protection devices, anapproximation of its physical proximity to the other circuit protectiondevices of the plurality of circuit protection devices; and storing, bysaid one of the circuit protection devices, the approximation of itsphysical proximity to the other circuit protection devices in the memoryof said one of the circuit protection devices.